1. Field of the Invention
This invention relates to the field of semiconductor processing and more particularly to the securing and disposal of consumable parts from a semiconductor processing tool.
2. Description of the Related Art
In the current semiconductor industry practice, many parts of semiconductor processing apparatus are treated as consumable parts either due to wear on the parts or due to the build up of excessively large film deposits which can contribute to particulate contamination of a semiconductor wafer process.
One example of a consumable part in a semiconductor processing apparatus is a free-standing window insert placed on an interior of a vacuum vessel window. The free-standing window insert protects the vacuum vessel window from, for example, deposits which can build on the vacuum window if unprotected. The free-standing window insert over time is replaced once its optical properties become insufficient for diagnostic purposes. By replacing the free-standing window insert, one avoids the time and expense of replacing the vacuum vessel window (a more costly item and one whose installation requires remaking and certifying of the vacuum seal).
Another example of a consumable part in a semiconductor processing apparatus is an electrode cover placed over a capacitive drive electrode in, for example, a reactive ion etcher. The drive electrode in a reactive ion etcher is typically a machined metallic electrode whose surface, if uncovered, is exposed to the reactive ion etch plasma atmosphere especially at high power levels or at edges where the field strength is higher. Such exposure can lead to undesirable metal contamination of the semiconductor wafer being etched. To prevent metal contamination, the drive electrode is provided with a cover made of, for example, silicon or quartz. Over time, the cover can etch or otherwise become unusable requiring that it be replaced. For example, even small changes in the physical dimensions of the cover can influence the resultant plasma uniformity in the reactive ion etcher. Due to the need to maintain plasma uniformity, such covers are changed frequently and become a consumable part whose proper disposal depends on the history of its exposure to aggressive chemistries and toxic substances in the semiconductor processing chamber.
Accordingly, one important environmental, health, and safety (EHS) issue in the semiconductor industry becomes that of disposal of used consumable parts from semiconductor processing tools. These parts are frequently exposed to toxic and dangerous chemistries during the lifetime of the consumable parts on the tool. The consumable parts need to be disposed of in a safe fashion and according to all applicable regulations. The chemicals that the consumable parts may have been exposed include extremely toxic materials such as for example hydrogen-fluoride (HF), arsine (AsH3), nitrogen-fluoride (NF3), etc. The disposal method depends on the chemicals that the part has been exposed to. In an environment where different wafer batches are subjected to different processes on the same tool, such as in a foundry semiconductor manufacturing plant, it is difficult to track what chemistries have been used in the tool since the consumable part was last replaced. Furthermore, it is typical that when maintenance on the tool is performed, there is no knowledge of the chemistries that the consumable parts have been exposed to, leading in some cases to the use of the safest, and invariably most expensive disposal approach. Such a fail-safe approach raises the cost of semiconductor processing.